It is desirable in building materials to have a wall covering or tile which has the appearance of stone. Stone is an attractive and durable material but is expensive to cut, heavy to transport, and difficult to install. Part of the problem with installation is that it is held up typically by adhesive, and the adhesive may not be strong enough to hold the stone tile in place, especially in the case of earthquake or tremors. Stone cannot be nailed in place, and drilling a hole for a mounting screw is expensive.
It is desirable to have a building material in the form of a slab or a tile which has the appearance of stone, but which is lighter than stone, easier to install and has more flexibility than stone.